In a power generating controller of a vehicle, electric power of a first power supply, employed at engine startup and during vehicle driving, is conserved to decrease power needed for charging of the first power supply and to reduce engine load by operation of a generator. In addition, deceleration energy, which has not been utilized conventionally, can be recovered to a second power supply, which enables use of power generation (regeneration) during deceleration of the vehicle, during which fuel is not required, to improve efficiency of the generative operation of the generator.